Disruption Mastery

Choose one from force- or tech-casting. You've mastered fighting and interfering with casters of the chosen type, confounding their concentration. You gain the following benefits:

• When a creature within 30 feet of you that you can see casts a power, they provoke an opportunity attack from you.
• You have advantage on saving throws against powers cast by creatures you can see if you've dealt damage to them since the start of your last turn.
• Whenever you force a creature to make a saving throw to maintain concentration, the DC for the saving throw increases by an amount equal to your proficiency bonus.